Globalization is characterized by the development of communication technology makes people more easily connect with others. One of the significant developments now is the sale and purchase transactions online or E-Commerce.Penjual and buyers do not need to face to face (transaction to face) to make transactions and buy, but only need to have an internet connection that will bring them in the virtual world. a legal review is conducted to prevent the occurrence of legal disputes between the parties. The approach method used in this research is empirical juridical approach. The study was conducted in the city of Semarang, which was determined pourposively. Data collection by literature study and interview. Qualitative analysis with deduction and induction methods. The results showed that the main principle of online transactions in Semarang prioritize the trust aspects between the parties. Principles of online transaction security security such as guarantee on the identity of seller / buyer, payment gateway security, security guarantee and reliability of electronic commerce website have not become main concern for sellers and buyers, especially on small to medium scale transaction with value nominal transaction that is not too large. The conclusion is that the legal protection for the consumer has not been reached optimally in the sale and purchase agreement on line.
Keywords: Consumer Protection, agreement, buying and selling